脱盐处理对钢筋-砂浆的电化学特征影响

运用半电池电位法、恒电流脉冲暂态响应和交流阻抗技术，测度了3种钢筋－砂浆试件的电化学特征。测试结果表明，经电化学脱盐处理试件的钢筋电位正移，RC和传递电阻Ret值增大。电化学脱盐处理具有使活化钢筋恢复钝化的趋势。     

混凝土多轴强度与变形特性的试验方法

综述研究混凝土多轴强度与变形特性试验设备的组成,对试验中试件居中、消减试件表面摩擦、应力与应变的量测以及拉力的施加等技术难点提出了相应的技术措施,并给出了混凝土多轴强度与变形特性试验的基本操作过程.     

混凝土电化学脱盐模拟及其影响因素分析

电化学方法可以用来对含有氯离子的混凝土进行脱盐。电流密度的大小和环境温度的高低是影响电化学脱盐效率的主要因素,过大的电流密度会对钢筋混凝土的性能产生一定影响,而较低的温度会降低脱盐效率。基于氯离子输运方程和温度对氯离子扩散系数的影响,建立了氯离子输运数值模型,得到了不同工作电流密度和温度下混凝土的电化学脱盐效率。结果表明：温度对脱盐效果影响显著,较高温度（303.15 K）时的氯离子渗透系数是较低温度（273.15 K）时的8.8倍;随着温度的升高,取得同样脱盐效果所需要的电流越小,即在较高温度环境下可以使用较低电流达到较高的脱盐效率。     

电化学脱盐防腐技术的室内试验研究

通过室内试验,研究了电化学脱盐技术参数和混凝土技术参数对电化学脱盐效率的影响。试验结果表明,采用适当的技术参数能够脱除混凝土中的Cl^-,使活化钢筋恢复钝化,从而达到钢筋防腐的目的。     

锈蚀钢构件安全评定指标初探

钢结构在长期运行过程中,由于周围环境的影响,钢构件表面发生不同程度的锈蚀,当锈蚀程度达到一定量时,将对钢结构造成安全隐患。应用粗糙度理论对钢材表面点蚀进行了分析,采用一组低碳钢试件进行试验研究,首先对试件进行人工化学锈蚀,除锈后再利用粗糙度检测仪对试件表面锈蚀情况进行检测。绘出了试件表面锈蚀坑轮廓图,提出了两种锈蚀坑缺陷面积的计算方法,初步提出了用缺口系数来描述锈蚀钢构件安全评价指标,该概念的提出为进一步研究锈蚀钢构件、乃至钢结构安全评定提供了一种新思路。     

钢筋混凝土电化学萃取氯离子研究进展

电化学萃取氯离子作为一项新型高效的钢筋混凝土防护技术,通过外加电场迫使混凝土中的氯离子从钢筋附近迁移至混凝土表面,同时使钢筋重新恢复钝化。本文综述了近年来国内外在此方面的研究进展,系统地介绍了电化学萃取氯离子的基本原理、装置选择与萃取参数确定、影响因素和电化学萃取氯离子对混凝土宏、微观性能的影响。同时结合目前研究现状对需要进一步研究的问题提出了相应的建议。     

混凝土参数对沉积效果的影响

就电沉积方法修复混凝土裂缝中混凝土参数对沉积效果的影响进行试验研究,测定了沉积过程中的试件质量增加率、表面覆盖率及裂缝愈合率,结果表明:在该文试验条件下试件质量增加率及裂缝愈合率随水灰比的增大而增大,表面覆盖率随水灰比的增大而减小;试件质量增加率、表面覆盖率及裂缝愈合率随保护层厚度的增大而减小;试件表面覆盖率及裂缝愈合率随裂缝宽度的增大而减小,质量增加率随裂缝宽度的变化规律不明显.     

氯化物环境钢筋混凝土的腐蚀和牺牲阳极保护

介绍氯化物环境钢筋混凝土腐蚀破坏的基本原理和设计阶段应采取的腐蚀预防措施以及钢筋混凝土结构阴极保护和电化学脱盐防腐蚀技术.电弧喷锌或电弧喷铝锌铟合金、锌箔/导电黏结剂、锌网/水泥浆护套、锌网/压板和埋入式等牺牲阳极保护系统是国外近20年来研究开发的能够有效控制氯化物环境钢筋混凝土腐蚀的牺牲阳极保护系统.与外加电流阴极保护相比,牺牲阳极保护具有安装简便、在运行过程中不需要维护管理、保护效果可靠等优点,并能用于预应力钢筋混凝土结构,不存在氢脆危险.     

基于微生物矿化的砂体胶结强度及耐久性试验研究

微生物诱导碳酸钙沉淀技术(MICP)是岩土工程领域中新兴的新型绿色环保地基加固技术之一。基于砂土固化的力学性能和微观测试,研究了MICP技术的固化效果。研究结果表明,微生物水泥胶结砂柱最高强度可达37.9 MPa,抗渗性能可从胶结前的1.72×10^-2cm/s提高至7.66×10^-7cm/s;经100次冻融循环后,试件外观完整,无明显缺陷和掉砂;冻融50次时强度损失率为17.0%,胶结砂体具有良好的抗冻耐久性能。40 mm×40 mm×160 mm棱柱体标准试件抗压强度为13.5 MPa,抗折强度为4.5 MPa;70 mm×70 mm×70 mm立方体标准试件抗压强度为8.6MPa。微观结构检测可知,石英砂表面与颗粒之间沉积着不同数量的方解石,随着胶结强度的增加,方解石沉积量逐渐提高至趋于稳定,生成量为10%～25%,砂柱孔隙率由34.8%逐渐降至12.1%,且微观孔结构逐渐细化、密实。     

磁化预处理-纳滤联合软化水过程的研究

纳滤目前是软化脱盐领域的一项重要技术并具有广阔应用前景,但膜面结垢会严重降低其操作性能,因此对纳滤的防垢抑垢研究非常重要.本研究在不同操作条件下考察了3种纳滤膜(NF90、NF270和NF-)的软化水过程,并首次将磁化作为纳滤软化过程的预处理措施,使纳滤膜的操作性能得到有效改善.该技术具有简单、安全、能耗小、无二次污染的优点,弥补了当前某些化学法(加抑垢剂、调pH或化学清洗)和物理法(改变流态)抑垢技术的不足.     

Brine Management: Substituting Chlorine with On-Site Produced Sodium Hypochlorite for Environmentally Improved Desalination Processes

The main environmental problem related to the desalination of seawater is the brine discharge coming from the processes of desalination of seawater. For coastal desalination plants, the most practical and least expensive brine disposal method is to discharge it into the sea at the plant’s outfall. However, there are several harmful environmental effects caused by this direct discharge. This discharged brine (concentrate wastewater) has many properties, which badly affects the environment. It consists of highly concentrated salts and any un-reacted pre-treatment chemicals. It also brings with it heavy metals resulting from the corrosion of tube and flash chamber wall material. Therefore, the largest impact of desalination on the environment occurs at the outfall of the desalination plant. This work addresses the problem of brine or wastewater generated from desalination production process. The work was conducted with the objective of shedding light on the business opportunities associated with brine wastes by using the brine for on-site generation of sodium hypochlorite. Sodium hypochlorite is a useful and valuable chemical product. It is the most widely used active chlorine compound in disinfection. In general, the suggested experimental process was aimed at the dual benefit of on-site generation of sodium hypochlorite and reducing the concentration of the brine. Therefore, the process will not only generate the sodium hypochlorite, but also will protect the environment.     

舟山大中型海岛海水淡化技术研究

通过对海水淡化技术在舟山海岛地区的适用性分析,得出海水淡化是解决舟山大中型海岛缺水问题的有效途径的结论。然后以舟山本岛为范例,研究舟山市大中型海岛海水淡化的整个工艺流程,探讨了大规模取水工艺、大型海水前处理工艺、淡化处理装置、海水净化后处理和利用问题,为舟山市其他大中型海岛实施海水利用起到示范作用。     

Optimization of Osmotic Desalination Plants for Water Supply Networks

Water scarcity and the poor quality of water resources are leading to a wider diffusion of desalination plants using the Reverse Osmosis (RO) process. Unfortunately, the cost of a cubic meter of fresh water produced by an RO plants is still high and many efforts are in progress to increase the efficiency of the membranes used in osmotic plants and to limit the energy required by the process. A further reduction of the energy cost could be obtained by an optimal operation of the desalination plant so reducing the hourly energy cost, or by coupling the RO plant with an energy production plant based on direct osmosis (Pressure Retarded Osmosis PRO).The economic viability of the desalination process has been analyzed until now without accounting for the integration of the RO plant with the existing water network. This analysis is developed in the present paper with reference to a hypothetical change of water supply in a real network, where a desalination plant is used to satisfy the fresh water demand. Several scenarios will be analyzed to assess the minimum cost of fresh water production and water supply to the network, including the use of energy recovery systems, such as an integrated use of RO and PRO processes, or the regulation of pressure at the network intake by a micro hydro power plant.     

膜法水处理技术在农村饮水安全中的应用研究

膜法水处理技术已经成为西部缺水地区进行苦咸水淡化、解决生活饮用水的主要方法之一。本文讨论了在农村饮用水处理中的几种膜工艺流程,分析了农村饮水处理中8套反渗透或纳滤膜苦咸水淡化系统的工艺参数。结果表明膜法淡化高含盐量苦咸水,出水水质均可达到或优于国家生活饮用水卫生标准,可以解决缺水地区的生活饮用水问题。     

反渗透处理高盐化工废水的试验研究

以经过两级混凝-超滤预处理后的化工废水为研究对象,通过试验考察了反渗透脱盐工艺处理高盐废水的效果和工艺稳定性。通过反渗透脱盐率和膜通量的变化来判定运行条件和进水水质对膜性能的影响。结果表明:系统稳定运行后对COD、电导率的平均去除率分别为94.38%、98.20%。在恒定压力(0.85 MPa)下,当进水TDS为3 500 mg/L时,膜性能稳定,膜通量衰减速率为0.008 6 L/(m2.h),在进水TDS>4 500 mg/L时脱盐率与膜通量随进水浓度的增大急剧下降。阻垢剂投加量为3.0~4.0 mg/L时,系统稳定运行150 h内压差稳定在0.04~0.07 MPa,出水满足该厂部分工艺用水的水质标准。     

宁夏青铜峡灌区水土化学场演化态势初步分析

本文以研究区翔实的水土化学多年动态测试资料为依据，勾划了3个时段9个化学参数值分布的系列图表，揭示了水土化学时空演化的规律性，以及两者演化联动的异同性。指出灌区水土经历了脱盐淡化的进程；由于地下水位居高不下，次生盐渍化仍在发生，减少引黄灌溉水量和降低地下水位才能确保土壤朝向脱盐良性循环发展；提出引用黄河水量、开发地下水和回用沟排水的多源灌溉；发展农、林、牧、果多种经济，提倡生态农业，推广种植耐旱耐盐作物。     

堵港蓄淡水库水体淡化预测研究

本文采用Delft3D三维分层模型研究堵港蓄淡水库水体淡化过程。用浙江省漩门二期堵港蓄淡水库长历时观测资料对模型进行验证和参数率定，水位、盐度及其分层的计算结果和观测资料基本吻合;在此基础上，该模型用于预测2004～2006年漩门二期堵港蓄淡水库在设计水文条件下运行时库内水体淡化过程及其效果。计算结果表明水库表层水体受径流影响较大，盐度下降很快，致使盐度分层明显，枯水年局部表层水体会出现返咸现象；深潭底部水体淡化很慢，应采取排盐措施。     

电吸附除盐后续工艺电解水催化还原去除硝酸盐的研究

针对碳气凝胶电极电吸附除盐工艺去除硝酸盐过程中存在的问题,采用电解水催化还原工艺作为其后续工艺,在原碳气凝胶电吸附除盐工艺装置上,进行了一系列平衡试验,对其影响因素进行了研究.结果表明,可以在不增加任何设备的情况下,大幅提高碳气凝胶电极电吸附除盐工艺去除硝酸盐的效果,并使电极得到再生.     

Analysis of the Water Resources Status in Kuwait

The acute lack of natural water resources in Kuwait is indisputable. The country essentially has one limited natural water resource that is groundwater, while the majority of the country's demands are met by seawater desalination. Notwithstanding this scarcity calls for careful foresighted utilization of the water resources, no clear plans is being followed. Attempting to initiate the planning process, this paper gives an assessment of the current status of water resources availability, production, future demand and expected increases in production, in Kuwait. While the desalination and wastewater reuse are only bounded by economical considerations, considerable efforts have already been made in assessing the baseline of the groundwater resources in Kuwait; nonetheless, no estimation is available of the aquifer system potential for sustainable development or even mining. The total water budget in 2001 is estimated at 655 Million m³, with desalination, groundwater production, and wastewater reuse constituting 59%, 32% and 9% respectively. The projected water demand for 2010 is 1020 Million m³. The plans of the Ministry of Electricity and Water and the Ministry of Public Works indicated that groundwater would cover 52% of the planned additional production, while desalination and wastewater reuse would cover 44% and 4% respectively. While the proposed increase in groundwater production would inevitably consume the only natural water resource of the country, only 40% of the generated wastewater is to be utilized. The absence of integrated planning is also manifested in the total planned production that surpasses the projected demands by more than 17%.     

Evaluating the economic viability of solar-powered desalination: Saudi Arabia as a case study

Abstract

This article constructs a cost calculator to estimate the economic competitiveness of solar-powered desalination in Saudi Arabia. Solar desalination is defined as a plant that obtains solar energy from a closed system. This is done to focus the investigation on desalination technologies, rather than the efficacy of replacing conventional energy sources with renewables in an integrated electricity grid. The results suggest that current options for solar-powered desalination are not cost-competitive compared to incumbent technologies in Saudi Arabia. The article offers insight into where costs must decrease before solar technologies are economically competitive in the country.